GFAP and medulloblastoma: Three groups of C57BL/6 mice were analyzed: (a) TRE-SmoA1 mice: the oncogenic gain-of-function allele of Smo, i.e., SmoA1, is not expressed in the absence of GFAP-tTA in these negative control group mice; (b) [GFAP-tTA;TRE-SmoA1] mice: all mice develop medulloblastoma in this positive control group; (c) [GFAP-tTA;TRE-SmoA1;AMPKα2−/−] mice: this test group allows us to assess the extent to which AMPKα2 KO modulates tumor incidence.